Mine roof support



Feb. 6, 1968 w. WEIRICH ETAL 3,367,117

MINE ROOF SUPPORT Filed Feb. 2, 1965 4 Sheets$heet 1 Wrnvroxay Feb. 6, 1968 w. WEIRICH ETAL MINE ROOF SUPPORT 4 Sheets-Sheet 2 Filed Feb. 2, 1965 Feb. 6, 1968 w. WEIRICH ETAL MINE ROOF SUPPORT 4 Sheets-Sheet 3 Filed Feb. 2, 1965 Feb. 6, 1968 w. WEIRICH ETA]. 3,367,117

MINE ROOF SUPPORT Filed Feb. 2, 1965 4 Sheets-Sheet 4 United States Patent 3,367,117 MINE ROSE SUPPQRT Walter Weirich and Willy Watermann, Dortmund, Germany, assignors, by mesne assignments, to Gewerirschaft Eisenhutte Westfalia, Altlunen, Germany, a corporation of Germany Filed Feb. 2, 1965, er. No. 429,779 Claims priority, application Germany, Feb. 4, 1964, H 51,579 6 Claims. (Cl. 6145) ABSTRACT OF THE DISCLGSURIE The invention relates to a support structure for mine roofs which may be advanced progressively through the work area of a mine as excavation takes place. The structure includes opposed pairs of telescopable props between which a horizontally extending power cylinder is positioned. The power cylinder includes telescopable members provided with oppositely extending brackets which, in turn, include arms that cooperate with the telescopable props. By reason of the brackets and arms and the manner in which they are connected to the support structure, the telescopable props may be folded over the power cylinder for transport.

The present invention relates to improvements in mining apparatus and, more particularly, to means for su-pporting mine roofs during the course of underground excavating.

Mine roof supports of this general type have been disclosed in an earlier patent application entitled, Mine Roof Support, filed Aug. 21, 1964, and given Ser. No. 391,149, now Patent No. 3,328,968 and which is also assigned to the assignee of this application.

In this earlier application there is disclosed a walking mine roof support which comprises elongated horizontal advancing means arranged to move the support progressively stepwise toward the mine face in an underground excavation, a pair of extensible and contractible leading pit props which are located at the opposite sides of the advancing means, a pair of extensible and contractible trailing pit props which also are located at the opposite sides of the advancing means, a floor-engaging sole plate articulately connected to the lower end portion of each prop, and a novel articulate connection between the props, sole plates and advancing means. The connection comprises two laterally extending hinges which are connected to the advancing means and include links or levers adapted to pivot about the axes which are parallel with the longitudinal extension of the advancing means, and such links carry detachable resilient elements in the form of suitably configurated leaf springs which are assembled into two groups of packages, one at each side of the advancing means and each including an upper package and a lower package. The packages have forwardly and rearwardly extending arms and the arms of each upper package are articulately and detachably connected to median portions of the props at a level above the respective hinge. The arms of the lower packages are articulately and detachably connected with such sole plates which are located at the same side of the advancing means. In such a manner, the sole plates and the packages are free to move relative to each other as well as relatively to the advancing means. Moreover, the props are free to move not only with reference to the advancing means but also with reference to each other as well as with reference to the sole plates whereby their roof bars can yield to unexpected obstructions when the mine roof support is caused to advance toward the mine face,

3,367,117 Patented Feb. 6, 1968 and the sole plates are also free to follow the outlines of an uneven mine floor. Furthermore, and while the props are free to perform limited movements with respect to positions in which their axes are normal or nearly normal to the plane of the mine roof, they are held against excessive swinging, tilting and similar movements such as could move the roof bars in positions in which they are unable to properly engage the mine roof when the props are extended.

With known roof trusses, of which the essential improvement over the prior art is supposed to consist in the fact that the advancing means remains relieved of twisting forces, these connections, keeping in mind their operation, are essentially formed in one piece and are detachably connected, if necessary, to the frames and/or to the guide means and sometimes elastically constructed to accommodate irregularities of the floor.

These designs, although working satisfactorily in flat locations, have been found to have the disadvantage that they cannot accommodate the varying condition of the stratum or vein, particularly the degree and direction or stretch of the inclination or dip, because no means is provided whereby connecting parts between the props and the guide can be adjusted and the working or operating conditions suitably changed.

For the purpose of counteracting the inclination of the mine support props in a dip, it already has been suggested that they can be supported from an erected frame associated with the same truss in a definite position with regard to the skid by means of at least one supporting spring secured to the frame. Preferably, in such an arrangement the props are given a bias counteracting the dip.

It has now been found possible to further improve the already substantial advantages procured by these measures if in addition the position of the frame on the whole can be made to accommodate the degree and stretch of the dip, as well as the unevenness of the floor.

Accordingly, in this invention, the support truss has two parallel upright alternately advancing prop means between which is disposed the longitudinal advancing means which, in turn, includes guide means, one located inside of the other, that transmit the twisting forces without hindrance. The outer and inner guide means are detachably connected by hinge means to respective ones of the prop means. The connection between the prop means and the guide means is made detachable by using a linkage arrangement which, in further explanation of the invention, is made positively or tensionally adjustable by means of an eccentric bolt and a key.

This construction makes it possible for both prop means to accommodate for local characteristics, particularly the degree and the direction or stretch of the dip, and it lends to the props or to the prop anchorages, a corresponding preferably biased, position with respect to the dip.

Not only do the restoring forces of the spring (not shown) holding the props resist the movements operating in the direction of the dip, but so do the restoring forces of the springs holding the prop feet and the ground beam leaf springs, because the springs of the corresponding frame side tend to restore themselves to their normal position, when the props are relieved, thereby appreciably opposing the inclination of the props in the presence of a dip.

Compared to the known embodiments, the proposed steps have the further advantage that the trusses, after having been taken apart at the hinged connections, very simply can be collapsed, with or without the prop, for transporting or storing as spare parts; or by uncoupling all connections, it can be reduced to a convenient group of small parts.

Of course, there are known embodiments employing screws or connections comprised of lock or strain pins that permit taking the truss completely apart. Aside from the disadvantage that connections of the one-piece ground beam are not adjustable, the connection between parts must be completely uncoupled and later again put back together, which entails considerable expenditure of time as well as energy.

Although it differs from the support trusses described above even in the system that it employs, a known walking support frame has the feature that the support frames can be collapsed, for transporting, down to the piston rod of the feed cylinder located therebetween.

That the support frame can be collapsed down to the piston rod of the pushing cylinder has, nevertheless, the decided disadvantage that the rigidity of the whole support truss is substantially reduced in the presence of steep dips, because the piston rod and the surrounding cylinder act as a hinge during the walking of a truss half.

It has turned out that these known arrangements possess certain difficulties in maintaining the frame support normal to the stratification (in other words, preserving a rigid shape of the truss) over a period of time, because in the presence of steep dips even the frame supports that are connected together with additional rods progressively lean or bend.

Lest the operation be questioned, it already has been suggested that the above-mentioned disadvantages can be minimized by employing additional changes in the socalled rods, without, however, being able entirely to rectify the faults arising from the twisting of the system about, and the transfer of forces by, the piston rod.

On the other hand, the forces in an advantageous manner can be transmitted by the proposed hinged coupling located between the guide means and the frame and by the adjustability of the positively connected hinge coupling. The truss accommodates each and every dip and yet in a simple manner can be folded up or separated into a number of individual components.

Moreover, the proposed embodiment assures a simple interchangeability of worn out or damaged parts and, because of the tensioning means used, offers a compensation for working tolerances or for the amount of Wear. Thus, no great demand is placed upon manufacturing precision; and, because of the sturdy, simple and reliable embodiment, the rough underground operations are largely provided for.

The further proposed oblong holes or slots that extend as far as the stop faces of the keys and surround the eccentric bolts on one side, as well as the arrangement that permits the wedge to be inserted from either side of the pivotal arm, also adapt the invention to underground operation.

In this way the procedure for collapsing is appreciably sim lified without reducing the strength of the structural members, and the possibility is offered of choosing the most favorable direction, depending on the prevailing local conditions, from which to insert the wedge. The advantageous exploitation of the effect of the weight of the wedge also helps to assure that there is always a secure contact between the tensioning means, such that the possibility that the truss will come apart from jars and vibration suffered in operation is absolutely eliminated.

Accordingly, the principal object of the invention is to provide a linkage means which will permit opposed pairs of prop means to be folded crosswise over a longitudinally extending means disposed therebetween into an inoperative position.

Another object of the invention is to provide an eccentric pin means which cooperates with a wedge means to hold the truss components together during operation as well as to facilitate the separation thereof into individual components.

These and other advantages and features of the invention will be appreciated from the following description, and from the drawings, in which:

FIG. 1 is a front elevational view of the support truss of the present invention;

FIG. 2 is a partial plan view showing the linkage means extending from opposite sides of the longitudinally disposed advancing means;

FIG. 3 is a partial front elevational and sectional view of the linkage means taken on line HI-III of FIG. 2; and

FIG. 4 shows the linkage means folded for storage or shipment.

Turning now to the drawings, and more particularly to FIG. 1, there is illustrated an apparatus which is known as a mobile or walking mine roof support which comprises a pair of telescopable hydraulic pit props 2 and 3, each of which is adapted to support at its upper extremity a cap 2a and 3a, respectively, which may be raised and lowered relative to the roof of the mine as the apparatus is caused to progress through the mine.

The lower extremity of each of the aforesaid props are provided with sole plates which are associated therewith by means of suitable ball and socket joints thereby permitting the props 2 and 3 to slide along an uneven mine floor F, all of which will be readily understood from an examination of the aforementioned earlier application Ser. No. 391,149, filed Aug. 21, 1964.

With further reference to FIG. 1, there is shown a longitudinally extending power means 1 adapted for advancing the props 2 and 3 relative to one another through the mine, said means including longitudinally slidable telescopable elements 1a and 1b, each of which is provided with complemental IU-sh'aped brackets 4a and 4b, respectively, the end portions of each of which being provided with aligned apertures 1010 into which are inserted eccentric pins 8 that include. lever means 8a that facilitate operation of the apparatus as will be understood as the description progresses.

Turning now to FIG. 2, it will be noted that arms 5 and 6 are pivotally mounted relative to the brackets 4a and 411, respectively, by means of the pins 8 which are projected through means defining elongated openings 10a in the opposed depending flanges carried by said arms.

From an examination of FIG. 3 and particularly the partial sectional view of arm 5, it will be noted that a transversely extending stop means 11 is affixed between the depending flanges carried at the inner end of this arm (both arms 5 and 6 are constructed in this manner) and is thereby adapted to receive a Wedge-shaped headed key means 9 which is inserted through a perforation provided in the top wall of the pivotal arm and is brought into engagement with said stop means and the eccentric pin 8.

In the simple embodiment shown in FIG. 3, the pivotal arms 5 and 6 'are firmly secured to position the associated props 2 and 3 in an upright position and for use on a relatively flat surface. A further locking of the pivotal arms 5 and 6 to prevent movement out of a position such as exemplified in FIG. 3 may be accomplished by inserting a suplemental key means (not shown) between the rear face of stop means 11 and the confronting wall of bracket 13. It is also to be understood that the aforementioned surfaces may also be complementally formed into various configurations so that when they are brought into juxtaposed relation a rigid assembly is provided when the key 9 is introduced between the stop means 11 and the eccentric pin 8.

It is to be understood, of course, from a further study of FIG. 1, where the apparatus is shown being utilized on an uneven floor, that the pivotal arms 5 and 6 are not locked in a position such as exemplified in FIG. 3, but instead, the eccentric pin 8, carried in each arm, is adjusted to a position which will provide for movement of the arms 5 and 6 relative to their respective supporting brackets.

In FIG. 4 there is shown a collapsible or foldable arrangernent of the arms 5 and 6 which is easily achievable through the relative simplicity of construction of this apparatus and whereby storage or transportation may be accomplished by lowering opposed pairs of posts 2 and 3 crosswise over the longitudinally extending means 1 thereby considerably reducing the area thereof.

To achieve the foldable positioning of the arms 5 and 6, and as best shown in FIG. 4, the eccentric pin 8 is removed from perforation 10, whereupon the arms are swung upwardly until they are 'brought into contact with the inner wall 13 of the bracket and thereafter the pin 8 is reinserted into the aperture provided, but from the opposite side, thereby securing the arms in an inoperative position as previously explained.

Thus, it is believed to be apparent from the foregoing that by longitudinally shifting the advancing means 1 so that the brackets 4a and 4b are out of alignment with one another, the props 2 'and 3 can be swung inwardly and downwardly with the bolts 8 acting as hinge pins about which the spaced props can be rotated. Accordingly, when folded in this manner with the props fully telescoped or retracted within their cylinders, the upper extremity of one pair of props is nearly 'brought into a plane with the sole plate of an opposed pair of props.

After the folding operation, the resulting triangular form permits the room neded for storage or transportation to be very considerably reduced. Thus the trusses, even when the props and frames remain connected together, do not exceed the width of whatever conveys the truss.

Although only one embodiment of the invention has been depicted and described, it will be apparent that this embodiment is illustrative in nature and that a number of modifications in the apparatus and variations in its end use may be effected without departing from the spirit or scope of the invention as defined in the appended claims.

That which is claimed is:

1. In a mobile mine roof support including opposed pairs of prop means and telescopable longitudinally extending power means interposed therebetween and associated therewith for progressive alternate advancement thereof the combination comprising, longitudinally reciprocable transversely disposed bracket means carried by said telescopable longitudinally extending power means and arm means pivotally supported by said bracket means associated with means extending between each pair of prop means whereby said opposed pairs of prop means may be folded crosswise over said longitudinally extending means into an inoperative position.

2. In a mobile mine roof support as claimed in claim 1, wherein the pivotal arm means are associated with the bracket means by an eccentric pin means.

3. In a mobile mine roof support as claimed in claim 2, wherein the eccentric pin means includes a lever means for actuation thereof.

4. In a mobile mine roof support as claimed in claim 2, wherein wedge means are installed in means defining an opening in said pivotal arm means for adjustment thereof relative to said bracket means.

5. In a mobile mine roof support as claimed in claim 4, wherein the wedge means 'are removable from the means defining an opening in said pivotal arm means and are re-insertable thereinto in a diametrically opposed direction thereby permitting said arms to be locked into an inoperative position relative to said bracket means.

6. In a mobile mine roof support as claimed in claim 1, wherein the bracket has a U-shaped configuration including a surface area complemental to a transversely extending means carried by said pivotal arm means.

References Cited UNITED STATES PATENTS 3,174,289 3/1965 Rosenberg 6l45.2

FOREIGN PATENTS 1,178,813 1964 Germany.

896,098 1962 Great Britain.

JACOB SHAPIRO, Primary Examiner. 

